The present invention relates to a color reproducing system, and in particular to a color reproducing system for reproducing color of a subject image which has been photographed by a color image input device such as a digital camera or the like by a color image output device such as a monitor, a printer or the like.
Many of conventional color reproducing systems aim to reproduce color appearing desirably, while exact color reproduction is basically achieved to some extent in such an image which has been photographed by a digital camera. For this reason, since color image processing is automatically performed inside a camera, a user can obtain an image satisfying him/her to some extent without adjusting an output image.
On the other hand, Japanese Patent Application KOKAI Publication No. 11-85952 has disclosed a color reproducing system aiming to achieve exact color reproduction, where an XYZ image of a subject under observation illumination light on a reproduction side is obtained from a photographed image of the subject, using the spectral sensitivity of a camera, photographing illumination light spectral data on a photograph side, observation illumination light spectral data on the reproducing side, and the like, and the XYZ image is converted to signal values in a reproducing device in response to color reproduction characteristics of a reproducing device to be output.
Also, in Japanese Patent Application KOKAI Publication No. 11-96333, a method has been disclosed that an exact color reproduction is performed by photographing a color chart whose spectral reflectance is known in the same conditions as photographing in a subject and using the spectral reflectance of the color chart and the photographing signal, even when there is neither spectral sensitivity of a camera nor photographing illumination light spectral data. In these methods, it is required that the photographed image of the subject is modeled by wavelength integral of a product of the spectral sensitivity of the camera and the incident light spectrum of the subject to the camera. Or it is required to be calibrated to such data.
In Japanese Patent Application KOKAI Publication No. 10-285541, when image data is recorded in a recording medium (memory card) of an electric still camera, image processing information such as white balance or gamma correction which has been performed on photographed image data in addition to the photographed image data is recorded simultaneously therewith, and restoring processing is performed according to procedure reversed to the image processing when exact color reproduction is performed so that image signal before the image processing is obtained and image correction processing is performed in accordance with displaying characteristics of a displaying monitor device.
In an exact color reproducing system such as disclosed in Japanese Patent Application KOKAI Publication No. 11-85952 and No. 11-96333, as mentioned above, it is necessary to perform a processing for color reproduction on photographed image data on which such an image processing as a contour enhancement or the like has not been performed. Also, in order to perform exact color reproduction, data of the spectral sensitivity of a camera, photographing illumination light spectrum, observation illumination light spectrum and the like are required, and these data corresponding to photographed image data must be used in the color reproduction processing.
Also, the method which has been disclosed in Japanese Patent Application KOKAI Publication No. 10-285541 is structured such that, after image data has been subjected to such an image processing as white balance or shading processing, gamma correction and the like, it is recorded in a memory card and it is subjected to restoring process according to the procedure reversed to the recording procedure in recording/restoring processing of the image data, so that photographed image data which has not been subjected to the image processing is obtained. However, such an image processing as white balance, gamma correction or the like is not required for image processing for exact color reproduction originally, and a processing which makes it impossible to restore image data is performed in some cases. Also, it is a complicated task to cause various pieces of data required for color reproduction to correspond to image data pieces different in photographing conditions, and there often occurs a case where data correspondence can not be preformed exactly.
Accordingly, an object of the present invention is to provide a color reproducing system which can make selection about whether or not predetermined image processing is performed on input color image data according to an aspect of a color reproduction processing.